Pakistan’s airspace remained closed Thursday morning leaving thousands stranded and costing airlines millions of dollars in extra fuel charges to fly around the key flight corridor.
Pakistan closed its airspace Wednesday as tensions with India rapidly escalated, leading to shelling across the disputed border in Kashmir, and the shooting down of fighter jets on both sides.
All international and domestic commercial flights in and out of Pakistan are cancelled "until further notice," according to Pakistan's Civil Aviation Authority.
The move has disrupted many international flights, due to the unique geography of the region.
Many airlines rely on Pakistan airspace for their global routes, with the alternative diversions south into India economically unfeasible.
Thai Airways announced that all its European routes "departing near midnight of 27 FEB through early 28 FEB" were cancelled "due to sudden closure of Pakistani airspace as a result of tension between India and Pakistan."
Other airlines diverted or re-routed their flights and some had to make stops to take on extra fuel to complete extended journeys that avoided Pakistan airspace.
Singapore Airlines announced that some of its flights from Singapore to London would have to stop in either Dubai or Mumbai to refuel.
"It's major corridor and this is a serious disruption as all traffic has been pushed much further south over the top of the Arabian gulf," Aviation analyst Geoffrey Thomas told CNN. "You can't go further north as you are then flying over the Himalayas -- and you can't do that. You're locked into this corridor."